An island is valuable only when the room can circulate around it and the top supports a defined purpose.
Give the island a job
Preparation, cleanup, cooking, seating and storage have different requirements. Combining all of them can create a wide, expensive island with conflicts between hot surfaces, splashes and diners.
Test clearance with doors open
Measure from finished cabinet fronts and handles, not wall lines. Open dishwashers, ovens and refrigerators can require more working room than a simple aisle dimension suggests.
Compare a peninsula
A peninsula may provide counter and seating without requiring circulation on four sides. It can also create a bottleneck if it narrows the only entrance.
Plan services early
Island sinks, cooktops, receptacles and ventilation can add floor, electrical, plumbing and permit work. Confirm the benefit before relocating services.